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SOILS  LABORATORY 
MANUAL  ANDNOTE  BOOK 

EASTMAN  AND   DAVIS 


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SOILS  LABORATORY 
MANUAL  AND  NOTE  BOOK 


LIPPINCOTT'S 
FARM  MANUALS 

Edited  by  K.  C.  DAVIS.  Ph.D. 


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SOILS  LABORATORY 
MANUAL  AND  NOTE  BOOK 


COMPILED  BY 

JASPER  F.  EASTMAN,  M.S. 

PROFESSOR   OF  AGRICULTURE,  THE  NEW  YORK  STATE  SCHOOL  OF  AGRICULTURE  AT 
MORRISVILLE,  N.  Y. 

AND 

KARY  C.  DAVIS,  Ph.D. 

PROFESSOR  OF  AGRICULTURE,   KNAPP  SCHOOL  OF  COUNTRY  LIFE,   GEORGE    PEABODY 
COLLEGE  FOR  TEACHERS,  NASHVILLE,  TENN. 


21  ILLUSTRATIONS  IN  THE  TEXT 


PHILADELPHIA  AND  LONDON 
J.   B.   LIPPINCOTT  COMPANY 


COPYRIGHT,    1915,    BY    J.    B.    LIPPINCOTT    COMPANY 


I^AUiti 


Electrotyped  and  Printed  by  J.  B.  Lippincott  Company 
At  the  Washington  Square  Press,  Philadelphia,  U.  S.  A. 


FOREWORD 

Tliis  ]\Ianual  is  intended  for  the  use  of  students  studying  soils,  whether 
they  be  in  high  schools,  agricultural  schools,  or  in  colleges.  It  is  believed 
that  the  experimental  method  of  studying  soils  serves  to  fix  in  mind  their 
characteristics  and  the  principl(\s  concerning  their  best  management. 

The  equipmc^nt  to  be  used  in  performing  these  exercises  is  simple  and 
inexpensive.  In  a  number  of  exercises  suggestions  are  given  for  using  tin  cans 
instead  of  regular  soil  tubes,  and  other  similar  substitutions  are  possible. 

Acknowledgments  are  due  Ginn  and  Company,  Boston,  for  the  use  of 
certain  exercises  (4,  17,  25,  and  26),  somewhat  adapted  for  use  here  from 
"Soil  Physics  Laboratorj-  ]\Ianual,"  by  Mosier  and  Gustafson;  to  Prof.  E.  0. 
Pippin  of  Cornell  University  Department  of  Soil  Technology,  for  the  use  of 
exercises  3,  27,  and  29,  adapted  from  his  ''Laboratory  Guide  in  Agricultural 
Soils,"  used  by  Cornell  students  in  typewritten  form.  Many  of  the  publica- 
tions mentioned  in  the  reference  list  have  been  drawn  upon  freely  for  aid. 
Obligations  are  here  expressed  for  the  suggestions  received  from  many  books 

and  papei-s  on  the  subject. 

The  Authors 
April,  1915. 


4jn05.2 


CONTENTS 


PAGE 

Instructions  Concerning  Laboratory  Work  in  Soils 11 

Exercise    1. — Field  Study  of  the  Processes  of  Soil  Formation 13 

Exercise    2. — Taking  Soil  Samples 16 

Exercise    3. — Study  of  Soil  Grains 18 

Exercise    4. — Composition  of  Soils 20 

Exercise    5. — Soil  Classification 22 

Exercise    6. — Volume-Weight  or  Apparent  Specific  Gravity 23 

Exercise    7. — True  Specific  Gravity 26 

Exercise    8. — Heavy  and  Light  Soils 28 

Exercise    9.— Effects  of  Organic  Matter 30 

Exercise  10. — Other  Effects  of  Organic  Matter 32 

Exercise  11. — Influence  of  Weathering,  Organic  Matter,  Sand  and  Lime  on  a  Clay  Soil  34 

Exercise  12. — Effect  of  Lime  and  Other  Chemicals  on  a  Clay  Soil 36 

Exercise  13. — Total  Moi.sture  Determination 38 

Exercise  14. — Capillary  Moisture 40 

Exercise  15. — Hygroscopic  Moisture 42 

Exercise  16. — Capillary  Rise  of  Water  in  Soils  of  Different  Texture 44 

Exercise  17. — Effect  of  Too  Much  Organic  Matter  on  Rise  of  Water 46 

Exercise  18. — Percolation  of  Water  Through  Soils 48 

Exercise  19. — Clod  Formation 51 

Exercise  20. — Soil  Surface  and  Percolation.  . 53 

Exercise  21. — Capacity  of  Loose  and  Compact  Soils  to  Hold  Water 55 

Exercise  22. — Effect  of  Evaporation  on  Soil  Temperature 58 

Exercise  23. — Value  of  Mulches  in  the  Retention  of  Moisture 60 

Exerci.se  24. — Optimum  and  Critical  Moisture 63 

Exercise  25. — Drainage  and  Soil  Temperature 66 

Exercise  26. — Color  and  Temperature 6S 

Exercise  27. — Soil  Ventilation 71 

Exercise  28. — Amount  of  Organic  Matter  in  Soils 74 

Exercise  29. — Absorption  of  Plant  Food  by  Soils 76 

Exercise  30. — Testing  Soils  for  Acidity 7S 

Exercise  31. — Examination  of  Chemical  Fertilizers SO 

Exercise  32.— Study  of  Plowing 82 

Exercise  33. — Examination  anrl  Discussion  of  Tillage  Machinery 85 


ILLUSTRATIONS 


FIG.  PAGE 

1.  Soil  Auger IG 

2.  King  Type  of  Soil  Sampling  Machine 16 

3.  Bin  fob  Storing  Soils 18 

4.  Pint  Tin  Cans  for  Use  in  Taking  Soil  Samples 18 

5.  Soil  Sampling  Tube 23 

6.  Twelve-inch  Tube,  with  Solid  Bottom 23 

7.  An  Accurate  Scale 26 

8.  Drying  Oven 42 

9.  Moisture-proof  Chamber 42 

10.  Handy  Equipment  to  Show  Rise  of  Water  by  Capillarity 44 

11.  Frame  and  Glass  Tubes  for  Showing  Capillary   Rise   of  Water  in  Dif- 

ferent Soils 44 

12.  Galvanized  Tray  or  Tank 44 

13.  Percolation  Soil  Tube 48 

14.  Support  Block  for  Use  in  Holding  Tubes 48 

15.  Another   Simple    Form    of   Apparatus   to    Show    Percolation    of   Water 

THROUGH  Soils 48 

16.  Common  Soil  Tube ■ .  .  53 

17.  A  Good  Form  of  Cylinder  for  Mulch  Experiments 60 

18.  Preparing  Himself  for  a  Soil  Plowing  Contest 82 

19.  Sod  Plow  Which  Does  Not  Pulverize  the  Soil  Very  Much 83 

20.  Stubble  Plow 84 

21.  General  Purpose  Plow 84 


SOILS  LABORATORY  MANUAL 
AND  NOTE  BOOK 

INSTRUCTIONS    CONCERNING   LABORATORY  WORK  IX   SOILS 

1.  Students  will  he  expected  to  i)e  in  the  laborator}'  and  ready  for  work 
at  the  appointed  time  for  the  period  to  begin. 

2.  A  schedule  will  be  found  in  the  laboratory  indicating  the  exercise  for 
each  student  or  group  of  students  to  perform  for  each  period. 

3.  Students  will  be  held  responsible  for  the  breakage  of  all  apparatus. 

4.  Experiments  should  be  carefully  labelled  with  tlie  o^\Tier's  name  and 
set  away  before  leaving  the  laboratory. 

5.  Some  of  the  experiments  require  a  small  amount  of  daily  attention. 
This  must  be  given  in  all  cases  and  credit  will  be  allowed. 

6.  Experiments  should  be  completed  promptly  and  when  finished  the 
apparatus  should  be  cleaned  as  quick!}'  as  possible. 

7.  Each  experiment  must  be  written  up  promptly  after  the  time  that  it 
is  completed. 

8.  All  questions  should  be  clearly  and  fully  answered  in  the  note  book. 
The  report  for  two  experiments  should  never  be  confused — let  each  be  com- 
plete in  itself.  Note  books  will  be  graded  on  correctness  of  the  results  of 
the  experiments,  the  way  in  which  the  experiment  is  written  up,  and  the 
neatness  of  the  work. 

9.  Before  commencing  an  exercise,  read  over  the  object  and  directions 
ver>^  carefully.  Be  sure  that  you  understand  clearly  what  is  to  be  done  before 
you  commence  work. 

10.  The  following  list  of  reference  books,  along  with  the  text-books  in 
use  by  the  students  should  be  consulted  in  writing  up  the  results  of  the 
exercises.    If  possible,  they  should  be  on  a  special  shelf  in  the  library. 


(12)  INSTRUCTIONS  CONCERNING  LABORATORY  WORK  IN  SOILS  (Con.) 

REFERENCE  BOOKS 

Soils Fletcher. 

The  Soil Hall. 

Agriculture,  Vol.  I Brooks. 

Soils Burkett. 

Soils Hilgard. 

Physics  of  Agriculture King. 

Soil  Management King. 

Farmers  of  Forty  Centuries King. 

Rocks,  Rock  Weathering  and  Soil  Formation.  .  .Merrill. 

Rocks  and  Soils Stockbridge. 

Physical  Properties  of  Soil Warington. 

The  Fertility  of  the  Land Roberts. 

Irrigation  Farming Wilcox. 

Soil  Culture  Manual Campbell. 

Dry  Farming Widtsoe. 

Engineering  for  Land  Drainage Elliot. 

Fertilizers  and  Crops VanSlyke. 

Soil  Fertility  and  Permanent  Agriculture Hopkins. 

Soils Lyon  and  Fippin. 

Bacteria  in  Relation  to  Country  Life Lipman. 

Soils  of  the  United  States Bulletin  96,  U.  S. 

Bureau  of  Soils. 

"If  a  man  can  write  a  better  book,  preach  a  better  sermon,  or  make  a 
better  mousetrap  than  his  neighbor,  though  he  buikl  his  house  in  the  woods, 
the  world  will  make  a  beaten  track  to  his  door." 


Dat(>:: 

EXERCISE  1  (13) 

Field  Study  of  Processes  of  Soil  Formation 

PLAN 

A.  Examine  a  sample  of  soil  and  name  all  of  the  materials  of  which  it  is 

composed.  How  much  organic  matter  is  there  in  this  soil?  Show  clearly 
how  this  organic  matter  has  been  formed.  Compare  its  age  with  that 
of  the  inorganic  matter. 

B.  Study  the  work  of  the  various  soil-forming  agencies  which  you  find  and 

discuss  clearly  and  fully  the  part  which  each  of  these  different  actions 
plays  in  the  formation  of  the  soil. 

1.  Moving  Ice. — Look  for  deep  scratches  on  the  solid  rock  which  forms  a 

part  of  the  earth's  crust.  What  is  a  glacier?  How  did  it  act  in  the 
formation  of  soils  in  New  York? 

2.  Moving  Water. — Examine  the  banks  of  a  brook  and  find  where  the  land 

has  been  built  up  on  one  side  and  cut  away  on  another.  Explain  the 
smoothness  and  roundness  of  the  stones  and  other  material  in  the  bed 
of  the  brook.  AVhat  effect  has  size  upon  the  way  in  which  the  material 
is  deposited?  Walk  along  the  base  of  a  steep  hillside  and  note  tlie  effect 
of  water  in  bringing  do^^^l  soil.  Is  this  action  l)cneficial  or  injurious? 
Why?  How  does  a  water-formed  soil  differ  from  that  formed  by  ice? 
How  does  the  water  grade  the  soil  according  to  the  size  of  particles? 

3.  Chemical  Action  of  Air  andWat£r;  Weathering. — Why  do  some  rocks  seem 

to  crumble  easier  than  others?  Examine  an  old  stone  wall.  Do  the  rocks 
rest  as  securely  as  they  did  when  they  were  first  laid?  ^^'hat  has  caused 
certain  rocks  to  crack  open? 

4.  Changes  in  Temperature. — Show  clearly  how  the  forces  of  heat  and  cold 

may  cause  rocks  to  crumble. 

5.  Action  of  Living  Plants  and  Animals. — Look  for  lichens  growing  upon 

rocks.  What  is  the  condition  of  the  rock  underneath  and  how  do  these 
plants  act  as  soil  builders?  Look  for  the  roots  of  trees  growing  between 
rocks.  Discuss.  Do  j'ou  find  small  roots  of  plants  between  layers  of 
rock?    Look  for  the  work  of  earthworms,  also  other  animals. 

6.  Effects  of  Organic  Matter. — Examine  a  piece  of  iron  which  has  been  in  a 

manure  heap  or  a  pile  of  decaying  organic  matter.  Explain  the  action. 
Examine  a  swamp  and  note  how  it  has  filled  up.    How  is  muck  fomied? 

7.  TFi'/jf/.^.— Find  some  soil  transi)orted  by  winds.     Is  such  action  beneficial 

or  injurious  at  the  present  time?  Give  two  different  kinds  of  soil  which 
are  formed  ])y  the  wind  and  state  their  location,  composition,  and  agri- 
cultural value.  * 

C.  Examine  surface  soil  and  subsoil.     How  do  they  differ?     Describe  each 

carefully. 

D.  If  possible,  examine  the  soil  of  an  old  pasture  which  has  never  been 

plowed.  Is  the  dark-colored  surface  soil  as  deep  here  as  on  land  which 
has  been  cultivated  for  several  years?    Why? 


(14)  EXERCISE  1   (Continued) 

Notes  and  Report  of  the  Study 


EXERCISE  1  (Continited)  (15) 

Notes  and  Report  of  the  Study  (Continued) 


Urauc 
Date. 


(16) 


EXERCISE  2 


Taking  Soil  Samples 


Purpose. — To  show  students  several  methods  of  taking  true  samples  of  field 
soils. 

PLAN 

1.  Dig  a  hole  with  a  spade  to  the  depth  of  one  foot  (more  or  less  if  desired). 
Place  a  folded  newspaper  or  piece  of  oilcloth  to  form  a  pocket  in  the 
bottom  of  the  hole.  Then  with  the  spade  shave  off  a  uniform  slice  of 
soil  from  top  to  bottom  of  one  side  of  the  hole.  This  slice  should  be 
caught  in  the  paper  as  it  crumbles  and  should  be  saved  as  the  sample. 
If  it  is  desired  to  test  the  soil  for  moisture  content,  sample  should  be 


Fig.  1. — Soil  auger  for  obtaining  soil  samples  at  different  depths.  The  bit  should  be  about  IH  inches 
in  diameter.  This  auger  may  be  had  in  short  sections  for  ease  in  carrying  when  travelling  considerable 
distances. 


Fig.  2. — King  type  of  soil  sampling  machine.  The  opening  just  back  of  the  steel  cutting  edge  is  smaller 
inside  and  the  cylinder  larger  than  the  rest  of  the  tube.  This  makes  the  tube  more  easily  removed  from  the 
soil,  and  the  core  of  soil  is  removed  from  the  tube  by  inverting  it.  The  steel  shown  at  the  left  is  placed  in 
the  tube  and  may  receive  the  blows  of  a  hammer. 

placed  promptly  in  a  wide-mouthed  bottle  or  jar.  It  should  be  sealed  to 
prevent  the  escape  of  moisture. 

2.  A  common  way  of  taking  soil  samples  where  great  depth  is  necessary  is 

to  use  a  common  auger,  having  an  extra  long  shaft — the  bit  may  be 
from  one  to  two  inches  in  diameter.  Special  soil  augers  are  made  for 
this  purpose  (Fig.  1). 

3.  Soil  sampling  cylinders  are  also  used  for  taking  field  samples  (Fig.  2). 

They  are  made  of  heavy  iron  or  steel  tubing,  sharpened  at  one  end.  Just 
back  of  the  sharp  edge  the  opening  is  slightly  constricted  to  compress 
the  core  of  soil  so  that  it  may  be  more  easily  removed  from  the  tube. 
The  tube  may  be  driven  into  the  soil  by  the  use  of  a  sledge  hammer  or  axe. 


EXERCISE  2  (Continued)  (17) 

QUESTIONS 

1.  For  what  purpose  should  field  samples  ever  be  taken  by  farmers? 
"2.  Can  you  devise  a  method  of  taking  field  samples  easily  where  the  soil  is 
stony  or  gravelly? 

3.  What  may  be  learned  regarding  the  character  of  soil  while  the  sample  is 

being  taken? 

Note. — All  samples  should  be  properly  labelletl  to  show  from  where  they  were  taken, 
when,  and  to  what  depth. 

4.  Why  is  it  necessary  to  take  samples  from  the  subsoil  as  well  as  the  surface 

soil? 

5.  Does  soil  analysis  furnish  complete  knowledge  as  to  the  productiveness 

of  the  soil?    Why? 


Date. 


(18) 


EXERCISE  3 

Study  of  Soil  Grains 


Purpose. — To  become  familiar  with  the  composition,  color,  size  and  the 
individual  particles  in  a  soil  and  to  see  clearly  the  difference  between 
various  types  of  soils. 


Fig.  3. — A  suitable  form  of  bin  for 
storing  soils  in  school  and  college 
laboratories. 


Fig  4. — Pint  tin  cans  are  suitable 
for  use  in  taking  soil  samples.  The 
moisture  may  be  held  by  tightly  fit- 
ting covers. 


1.  Obtain  from  the  field  or  from  soil  supplies  in  the  laboratory,  samples  of 

the  following  soils:     sand,  sandy  loam,  loam,  clay  and  muck  (Figs.  3 
and  4). 

2.  Examine  these  soils  with  reference  to  the  following  points  and  record 

results  in  the  table. 
When  dry:   (a)  color,    (6)odor,   (c)  fineness  or  texture — coarse,  medium  or 

fine. 
When  moist:    (a)  color,  (6)  odor,  (c)  crumbly  or  plastic. 


*Adapted  from  Department  of  Soil  Technology,  Cornell  University. 


EXERCISE  3   (Continued) 
Physical  Properties  of  Soils 


(19) 


Soil 

Color 

Odor 

Texture 

Condition 

Dry 

Wet 

Dry 

! 

Wet 

Dry 

Wet 

Sand 1                        ' 

Sandy  loam 

Loam 

1               i               1 

Clay 1 

i                I                ! 

Muck 

3.  Examine  under  the  high  or  low  power  microscope,  samples  of  fine  gravel, 
coarse  sand,  medium  sand,  fine  sand,  very  fine  sand,  silt,  and  clay, 
sandy  loam  and  muck.  Make  drawings  of  each  showing  how  they  differ 
in  shape  and  relative  size. 


QUESTIONS 

1.  How  do  the  particles  in  each  of  the  samples  differ  in  color? 

2.  Name  the  first  seven  according  to  relative  size,  stating  their  diameter  in 

inches. 

3.  Compare  them  with  the  sample  of  sandy  loam. 

4.  How  does  the  muck  differ  from  the  others  in  texture  and  general  appear- 

ance? 


Grade. 
Date. . 


(20) 


EXERCISE  4 


Composition  of  Soils 
PtJRPOSE. — To  determine  the   composition  of  soils  by  the  sedimentation 
method. 


For  this  work,  samples  of  at  least  three  widely  different  soil  types  common 
in  the  localitj^  should  be  examined. 

1.  Place  about  10  cc.  of  the  soil  to  be  studied  in  a  dry  100  cc.  glass  graduate. 

2.  Fill  two-thirds  full  with  water  and  shake  vigorously  at  intervals  for  ten 

minutes.     Allow  to  stand  until  the  soil  has  settled.    Then  estimate  as 
closely  as  possible  the  proportion  of  the  different  grades  of  gravel,  sand, 
silt  and  clay  which  are  present. 
Repeat  this  operation  with  the  other  samples. 

Composition  of  the  Soil 


Kind  of  soil 

Organic 
matter 

Gravel 

Sand 

Silt 

Clay 

Consult  the  soil  survey  bulletin  (as  directed  by  the  instructor)  for  the 
results  of  a  mechanical  analysis  of  these  soils.  Then  plot  curves  showing 
graphically  their  relative  texture  and  the  proportionate  amount  of  the 
different  groups  of  separates.  Use  the  chart  on  page  78  of  "Soils"  by 
Lyon  and  Fippin  as  a  guide. 

QUESTIONS 

What  is  a  mechanical  analysis  of  a  soil? 
How  does  it  differ  from  a  chemical  analysis? 

How  do  the  mechanical  analyses  of  soils  made  by  the  U.  S.  Department 
of  Agriculture  differ  from  the  results  of  above  exercise? 

♦Adapted  from  "Laboratory  Manual  for  Soil  Physics" — Mosier. 


EXERCISE  4  (Continued) 


(21) 


50 
45 

■ 

35 
30 
25 
20 
15 
10 
5 

n 

I  FINE 
GRAVEL 


2  COARSE 
SAND 


3  MEDIUM 
SAND 


4  FINE 
SAND 


5  VERY  FINE 
SAND 


6  SILT 


7  CLAY 


Grade. 
Date. . 


(22) 


EXERCISE  5 


Soil  Classification 


Purpose. — To  enable  the  student  to  become  familiar  with  a  few  common 
soil  series  and  tj'pes. 

PLAN 

Describe  each  area  of  soil  studied  according  to  the  following  outline: 


1st  area 

2nd  area 

3rd  area 

Climate  of  the  section 

Method  of  formation 

Source  of  material 

Topography i 

Altitude 

Color  of  surface  soil 

Color  of  subsoil 

Drainage : 

Organic  matter 

Lime  content 

Rock :  amount,  shape,  kind 

Arrangement  of  matter .... 

Stratified 

Structure  

Complete  analysis 

Remarks 

Name  of  soil 

urade. 
Date. . 


EXERCISE  6 


Volume-weight  or  Apparent  Specific  Gravity 


(23) 


Purpose. — To  compare  the  weight  of  a  tube  of  soil  with  the  weight  of  a 
tube  of  water  filled  to  exactly  the  same  height.  This  result  will  give 
the  apparent  specific  gravity  of  the  soil  or  the  weight  of  soil  compared 
with  an  equal  volume  of  water.  If  desired  the  sample  may  he  taken 
with  a  tube  shown  in  Fig.  5. 


1.  Take  one  of  the  special  tubes  which  has  the  opening  at  the  bottom  plu^ 

with  a  cork  stopper  and  from  which  the  brass  strainer  has  been  removed; 
or  use  a  tube  with  solid  bottom  as 
in  Fig.  6.    (Schools  not  equipped 
with  soil  tubes  may  use  tin  cans.) 

2.  Be  sure  that  the  tube  is  dry.    Then 

weigh  it  carefully  on  the  balances. 

3.  Fill  the  tul)e  with  sand  to  within  one 

inch  of  the  top,  pouring  it  in  loosely. 
Weigh  carefully  on  the  balances. 

4.  Empty  the  soil  back  into  the  right 

bin  and  fill  the  tube  again,  but  this 
time  compact  the  soil  in  the  com- 
pacting machine.  If  no  compacting 
machine  is  available,  pack  the  soil 
by  dropping  the  tube  from  the 
height  of  five  inches  five  times  upon 
a  book. 

5.  Repeat  this  operation  for  all  of  the 


Fig.  5.  —  Soil  sam- 
pling tube  for  taking  a 
sample  of  surface  soil 
in  an  undi.sturbed  con- 
dition— useful  in  deter- 
mining    the     volume 

eight    of    soi 
field  condition. 


Fig.  0. — Twelve-inch 
tube  with  solid  bottom, 
for  use  in  determining 
volume-weight  and 
pore  space. 


the  tabic 

6.  Finally  fill  the  tube  with  water  to  exactly  one  inch  from  the  top  and  weigh 

carefully. 

7.  If  the  real  specific  gravity  of  these  soils  is  known  secure  them  from  the 

instructor  and  then  compute  the  porosity  of  each.    See  (3)  below. 

8.  The  following  formulas  may  be  followed  in  working  out  the  calculations: 

Volume-weight  =  Weight  of  a  tube  full  of  soil  (1) 

Weight  of  Soil 
Weight  of  Water 


Apparent  Specific  Gravity 


^^O-lAS^^n^H 


(2) 
(3) 


(24) 


EXERCISE  6  (Continued) 
Apparent  Specific  Gravity 


Wt.soil+tube 

Wt. 

ube 

Wt.  soil 

Ap.  sp.  gr. 

Porosity 

Soil 

Com- 
pact 

Loose 

Com- 
pact 

Loose 

Com- 
pact 

Loose 

Com- 
pact 

Loose 

Com- 
pact 

Loose 

Sand 

Sandy  loam .... 

Loam 

Clay 

Muck 

Weight  of  equal  volume  of  water. 


QUESTIONS 

1.  From  the  result  secured  calculate  the  weight  per  cubic  foot  of  each  of 

the  soils. 

2.  Finally  calculate  the  weight  per  acre  foot. 

3.  What  is  meant  by  the  volume-weight  of  soil? 

4.  Give  a  definition  of  specific  gravity. 

5.  What  is  the  difference  between  apparent  specific  gravity  and  real  specific 

gravity? 

6.  What  is  meant  by  porosity? 

7.  What  is  the  porosity  of  the  average  soil? 

8.  State  clearly  the  necessity  for  pore  space  in  soil. 

9.  What  influence  has  (a)  organic  matter,  (6)  texture, 

the  porosity  of  a  soil?    Upon  the  weight  of  a  soil? 

10.  Which  is  heavier,  a  coarse  or  a  fine  soil?    Why? 

11.  What  does  this  exercise  show  concerning  the  comparative  weight  and 

apparent  specific  gravity  of  land  recently  plowed  and  land  unplowed? 


(c)  structure  upon 
Why? 


EXERCISE  6  (Continued)  (25) 


(26) 


Date. 


EXERCISE  7 


True  Specific  Gravity 
Purpose. — To  determine  the  real  specific  gravity  of  any  sample  of  soil. 


1.  Fill  a  specific  gravity  bottle  with  distilled  water  and  weigh  it  (Fig.  7). 
Pour  out  part  of  it  and  add  ten  grams  of  oven-dry  soil.    Heat  the  content 


■iiiiiiiiii^^ 

Fia.  7. — An  accurate  scale  with  agate  bearing  is  a  valuable  part  of 


L'ciuipment  for  studying  agricultural 


slightly  to  drive  out  any  air  adhering  to  the  soil.    Now  refill  the  bottle 
with  distilled  water  and  weigh  again. 
2.  Divide  the  loss  in  weight  of  water  into  the  weight  of  soil  to  find  the  specific 
gravity.    Record  the  results  in  the  following  table. 

Specific  Gravity  of  Soil  Grains 


Wt.  bottle  and  waten    Soil,  bottle  water       Water  displaced  Specific  gravity 


Note. — Students  should,  if  possible,  compare  the  real  specific  gravity  of  sand,  clay, 
humus  soil  and  others. 

QUESTIONS 

1.  What  precaution  should  you  take  in  the  careful  performance  of  this 

exercise? 

2.  Why  are  specific  gravity  bottles  provided  with  glass  stoppers  having  small 

openings? 


EXERCISE  7  (Continued)  (27) 

3.  Give  a  definition  of  true  specific  gravity. 

4.  Of  what  value  to  the  farmer  is  a  knowledge  of  the  specific  gravity  of  his 

soil?     Would  it  indicate  anything  regarding  the  amount  of  humus  or 
the  amount  of  sand? 

5.  Name  the  four  principal  minerals  from  which  soil  has  been  derived.    State 

and  discuss  their  specific  gravities. 

6.  Wliat  is  the  average  specific  gravity  of  soil  grains? 

7.  Look  up  the  specific  gravities  of  sand,  silt,  and  clay  iind  discuss  them. 


Grade. 
Date. . 


(28)  EXERCISE  8 

Heavy  and  Light  Soils 
Purpose. — To  find  why  certain  soils  are  called  "heavy"  and  others  "light." 

PLAN 

1.  Fill  a  soil  tube  or  tin  can  with  dry  sand,  pack  well,  refill,  strike  off  with 

straight  edge  and  weigh.     Empty  the  vessel  and  weigh  it  while  empty. 
Record  results  in  the  following  table. 

2.  In  like  manner  determine  the  weights  of  the  same  volume  of  several  other 

soils,  such  as  black  humus  soil,  heavy  clay,  and  medium  loam. 

Results 


Wt-  soil  and  tube 


QUESTIONS 

1.  Arrange  the  soils  in  the  order  of  their  actual  weights. 

2.  Why  does  the  farmer  call  clay  soils  heavy  soils? 

3.  Are  the  so-called  heavy  soils  really  as  heavy  as  sandy  soils? 

4.  Why  are  sandy  soils  spoken  of  as  light  soils? 

5.  Would  humus  added  to  heavy  soils  make  them  plow  easily? 

6.  What  effect  would  sand  have  on  clay  soils  in  this  regard? 


EXERCISE  8  (Continued;  (29) 


Grade. 
Date. . 


(30) 


EXERCISE  9 


Effects  of  Organic  Matter 
Purpose. — To  study  the  effects  of  organic  matter  in  soils. 


Secure  directions  from  the  instructor  in  charge  as  to  where  the  samples 
of  soil  shall  be  taken, — one  from  a  plot  rather  free  from  organic  matter, 
the  other  from  sod  land  or  soil  otherwise  rich  in  organic  matter. 

Take  steel  cylinder  (Fig.  5),  a  heavy  block  of  wood  and  an  axe  or  hammer. 
Select  a  place  as  free  from  stones  as  possible  in  the  cultivated  ground. 
Carefully  drive  cylinder  into  the  earth  to  a  depth  of  seven  inches.  Dig 
out  around  it  with  a  spade  and  remove.  Transfer  the  soil  from  within 
the  cylinder  to  an  oilcloth  or  paper  and  from  there  to  a  glass  jar.  (In 
lieu  of  the  cylinder  method,  samples  may  be  taken  with  a  spade.  Equal 
volumes  may  be  compared  by  measurement  in  tubes  or  cans  filled  and 
packed  equally.) 

Repeat  the  same  process  in  the  sod  land. 

Bring  the  samples  of  soil  to  the  laboratory  and  weigh  each  carefully. 

Weigh  out  100  grams  of  each  soil  and  determine  the  amount  of  capillary 
water  in  each. 

Make  the  following  calculations,  using  the  entire  samples,  or  equal  volumes 
of  each. 


Weight  of  Apparent 

furrow  slice  sp.  gr. 


Per  cent,  of 
capillary  water 


Cultivated . 


Sod. 


QUESTIONS 

Describe  the  color  and  physical  appearance  of  the  two  soils. 
Which  weighs  the  more  and  why? 
Which  do  you  think  would  retain  the  more  water? 
Which  soil  has  the  greater  apparent  specific  gravity?    Why? 
Which  soil  has  the  greater  porosity?    Why? 
Which  soil  would  the  farmer  consider  the  more  productive? 
State  clearly  the  influence  of  constant  tillage  upon  the  organic  matter  in 
the  soil. 


EXERCISE  9   (Continued)  (31) 


Grade. 
Date. . 


(32)  EXERCISE  10 

Other  Effects  of  Organic  Matter 

Purpose. — To  study  the  effects  of  manure  and  organic  matter  on  the  water- 
holding  capacity  of  the  soil. 


Use  the  following  soils:  (1)  sand;  (2)  sand  with  10  per  cent  well-rotted 
manure;  (3)  sandy  loam;  (4)  sandy  loam  with  10  per  cent  well-rotted 
manure;  (5)  muck;  (6)  sand  v/ith  40  per  cent  muck. 

1.  Take  six  glass  or  metal  percolators  (Fig.  13)  and  in  the  bottom  of  each 

place  a  small  piece  of  folded  filter  paper.  If  necessary  moisten  the  filter 
paper  in  order  that  it  may  cover  the  bottom  opening  well. 

2.  In  percolator  No.  1  place  500  grams  of  sand. 

3.  Weigh  out  450  grams  of  sand  and  mix  thoroughly  with  50  grams  of  well- 

rotted  manure.    Place  in  percolator  No.  2. 

4.  Place  500  grams  of  sandy  loam  in  No.  3. 

5.  With  450  grams  of  sandy  loam  thoroughly  mix  50  grams  of  manure  and 

place  in  No.  4. 

6.  In  percolator  No.  5  place  500  grams  of  muck. 

7.  For  percolator  No.  6  thoroughly  mix  300  grams  of  sand  and  200  grams 

of  muck. 

8.  Make  the  soil  compact  by  allowing  each  percolator  to  drop  six  times 

upon  a  book  from  the  height  of  two  inches.  Be  careful  to  treat  each  the 
same. 

9.  Set  glasses  underneath  each  percolator  and  then  add  slowly  to  each 

sample  400  cc.  of  water. 

10.  When  percolation  has  ceased  measure  carefully  the  amount  of  water 

which  has  come  through.  Subtract  this  amount  from  the  amount  of 
water  which  was  added.  This  will  give  the  amount  of  water  held  by  the 
soil. 

11.  Record  results  in  the  following  table. 


EXERCISE  10  (Continced) 
Results 


(33) 


Kind  of  soil 

Grams  of  water                       Tons  of  water  held  by 
held  by  soil                                      acre  7  in- 

Sand ! 

Sand  with  10  per  cent  manure  ... 

Sandy  loam  

Sandy  loam  with  10  per  cent  manure  . 

Muck 

Sand  with  10  per  cent  muck 

i 

12.  Compute  in  tons  the  amount  of  water  held  by  each  mixture  for  an  acre 
furrow  slice,  assuming  such  an  amount  to  weigh  2,000,000  pounds. 


QITESTIONS 

1.  What  is  the  efTect  of  organic  matter  upon  the  structure  of  the  soil  and 

upon  its  ability  to  retain  moisture? 

2.  Why  is  some  of  the  water  which  percolated  through  of  a  straw  color? 

3.  What  does  this  water  contain  and  what  harmful  farm  practice  does  it 

suggest? 

4.  How  much  manure  should  be  applied  per  acre? 

5.  Which  is  the  better  farm  practice,  to  apply  10  tons  of  manure  per  acre 

every  4  years  or  20  tons  every  8  years? 

6.  Give  five  distinct  benefits  from  the  use  of  manure. 

7.  AVhy  is  manure  beneficial  on  muck  land? 

8.  State  clearly  the  best  method  of  handling  muck  for  the  purpose  of  improv- 

ing a  sandy  soil.     (Brook's  Agriculture,  Vol.  1,  pp.  90,  91.) 

9.  How  do  manure  and  muck  differ  in  their  power  to  improve  the  soil? 


Grade. 
Date. . 


(34)  EXERCISE  11 

Influence  of  Weathering,  Organic  Matter,  Sand  and  Lime  on 
A  Clay  Soil 

Purpose. — To  determine  best  system  of  management  for  a  clay  soil. 

plan  * 

1.  Take  five  of  the  shallow  square  pans  and  weigh  into  each  400  grams  of 

pulverized  clay. 

2.  To  pan  No.  3  add  100  grs.  of  muck  nnd  mix  thoroughly  with  the  clay. 

3.  To  pan  No.  4  add  ten  grs.  of  lime  and  mix  thoroughly. 

4.  To  pan  No.  5  add  10  grams  of  sand  and  mix. 

5.  Leave  pans  1  and  2  without  addition. 

6.  Add  water  slowly  and  mix  each  with  a  steel  spatula  to  a  stiff  puddled 

condition.    Be  very  careful  not  to  add  too  much  water. 

7.  Take  pan  No.  1,  which  contains  pure  clay,  and  scratch  with  a  knife  blade 

to  a  depth  of  one-eighth  of  an  inch  one-third  of  the  surface,  arranging 
the  scarifications  one-fourth  of  an  inch  apart  in  both  directions. 

8.  On  a  cold  night  set  the  untreated  pan  No.  2  out-doors  and  allow  it  to 

freeze  solid  in  its  wet  state. 

9.  Set  the  other  four  pans  away  and  allow  them  to  dry  out  thoroughly. 
10.  Later  examine  the  pans  and  answer  the  following  cjuestions. 

QUESTIONS 

1.  State  the  effect  of  muck,  lime,  sand  and  organic  matter  on  the  hardness 

of  a  clay  soil.    Discuss. 

2.  Does  the  sand  appear  to  have  improved  the  tilth  of  the  clay  soil?    Would 

it  be  profitable  farm  practice  to  apply  sand  to  a  clay  soil?    Why? 

3.  Does  freezing  tend  to  mellow  and  crumble  a  puddled  clay  soil?     What 

does  this  indicate  as  to  the  time  of  plowing? 

4.  How  are  the  ice  crystals  formed? 

5.  What  influence  do  the  checks  have  on  the  structure  of  the  soil? 

6.  From  the  results  of  this  experiment  outline  a  system  of  management  for 

a  heavy  clay  soil. 

7.  How  do  commercial  fertilizers  compare  with  manure  in  improving  a  clay 

soil? 

8.  What  form  of  lime  would  give  the  quickest  results  on  a  clay  soil?     (See 

next  exercise). 

9.  How  many  pounds  would  you  use  per  acre?    How  should  it  be  applied? 

*  Adapted  from  Department  of  Soil  Technology,  Cornell  University. 


EXERCISE   11   (Con-tinted)  (35) 


Grade. 
Date. . 


(36)  EXERCISE  12 

Effect  of  Lime  and  Other  Chemicals  on  a  Clay  Soil 
Purpose. — To  show  that  some  chemical  materials  cause  the  soil  to  l^ecome 

more  mellow  and  to  crumble  more  easily,  while  other  materials  have 

the  opposite  effect. 
FlocculaUon  is  the  collecting  together  of  very  fine  particles  into  clots  or 

granules. 

PLAN 

1.  Powder  thoroughly  in  a  mortar  four  ten-gram  samples  of  clay  soil  and 

place  in  glass  bottles. 

2.  Fill  the  bottles  about  two-thirds  full  of  water. 

3.  Leave  the  first  untreated  but  add  chemicals  to  the  other  three  bottles 

according  to  the  following  table.    Pour  some  of  the  solution  into  a  beaker 
and  then  measure  the  exact  amount  with  a  graduate. 

4.  What  difference  do  you  notice  in  the  appearance  of  the  solutions  in  the 

four  bottles? 

5.  Examine  some  of  the  material  from  each  bottle  under  a  microscope  and 

make  observations. 

6.  Allow  bottles  to  stand  and  note' time  required  for  the  particles  to  settle. 

Clean  carefully  the  beaker  and  graduate  after  each  solution  is  used. 
Results 


Kind  of  treatment 

Appearance  after  l-i  hour 

Time  required  to  settle 

No  treatment j 

20  cc  of  lime  water                                  1 

20  cc.  of  acid  phosphate I 

20  cc  of  nitrate  of  soda 

QUESTIONS 

1.  What  material  did  you  find  most  effective  in  producing  flocculation? 

2.  How  is  a  clay  soil  benefited  if  its  particles  are  brought  together  in  flakes? 

3.  What  form  of  lime  would  act  the  quickest  on  a  clay  soil? 

4.  What  form  of  lime  might  be  more  satisfactory  on  a  sandy  soil  ? 

5.  How  much  should  be  used  per  acre  on  a  sandy  soil  and  how  much  on  a 

clay  soil? 

6.  Under  what  conditions  would  lime  benefit  a  sandy  soil? 

7.  Discuss  the  action  of  acid  phosphate  on  the  soil.     Does  it  cause  soils  to 

become  acid?    How? 

8.  What  effect  has  the  continuous  use  of  nitrate  of  soda  upon  soil  structure? 


EXERCISE  12  (Continued)  (37) 


Uradc. 
Date. . 


(38) 


EXERCISE  13 


Total  Moisture  Determination 
Purpose. — To  determine  the  total   moisture   content  of  field  samples  of 
different  soils. 


2. 


Take  four  pint  jars  with  tight-fitting  tops.  Secure,  either  from  the  field 
or  greenhouse,  according  to  directions  from  the  instructor,  moist  samples 
of  the  following  soils — sand,  loam,  clay,  and  muck.  Bring  to  the  lab- 
oratory. 

Secure  four  round  evaporating  dishes  and  after  numbering  determine  their 
weight.  Next  weigh  into  each  a  fifty -gram  sample  of  the  soil  the  moisture 
content  of  which  is  to  be  determined. 

3.  Place  the  samples  in  a  drying  oven  the  temperature  of  which  is  slightly 

above  the  boiling  point  of  water  and  allow  to  remain  for  twelve  hours. 
Later  remove  to  a  dry  chamber  and  allow  to  cool.  Weigh  as  quickly  as 
possible.  Then  return  to  the  oven  and  heat  again  and  reweigh  in  order 
to  be  sure  that  all  moisture  has  been  driven  off. 

4.  Determine  the  total  moisture  by  dividing  the  weight  of  moisture  by 

weight  of  dry  soil. 
Several  samples  of  soil  taken  the  same  day  from  different  fields  will  enable 

the  student  to  determine  the  relative  water-holding  capacity. 
In  making  the  calculations  net  weights  only  must  be  used.     Eliminate  the 

weight  of  dish  in  each  case. 

Total  Moisture 


Weight 
of  dish 

Total  water 

Dry  weight  of 
dish  and  soil 

Dry  weight  of 

Soil 

Weight 
of  soil 

Weight  of 
dish  and  soi! 

moisture 

Sand 

- 

Loam ... 

Clay 

Muck 

i 

EXERCISE   13  (Continued)  (39) 


QUESTIONS 


1.  Make  a  drawing  illustrating  the  availability  to  plants  of  the  three  kinds 

of  water  found  in  field  soils. 

2.  State  two  ways  in  which  soil  moisture  is  lost. 

3.  What  proportion  of  soil  water  is  probably  lost  by  percolation? 

4.  State  the  methods  which  may  be  used  to  prevent  the  loss  of  water. 


Ortide. 
Date. . 


(40) 


EXERCISE  14 


•  Capillary  Moisture 

Purpose. — The  determination  of  capillary  moisture  in  samples  of  field  soil. 

Capillary  mmsture  is  that  water  which  is  held  in  the  soil  by  surface  tension 
of  the  soil  particles.  If  soil  is  exposed  to  the  air  it  can  be  entirely  evapo- 
rated at  room  temperature, 

PLAN 

1.  Take  four  pint  jars  with  tight-fitting  tops.    Secure,  either  from  the  field 

or  greenhouse,  according  to  directions  from  the  instructor,  moist  samples 
of  the  following  soils :  sand,  sandy  loam,  clay,  and  muck.  Bring  to  the 
classroom  and,  using  the  square  soil  pans,  determine  the  moisture  content 
of  the  soil,  as  follows: 

2.  Label  with  a  wax  pencil  and  weigh  on  the  balances  the  empty  pan.    Then 

immediatel}^  weigh  into  it  100  grams  of  the  moist  soil  as  quickly  as 
possible. 

3.  Do  the  same  with  the  other  soils. 

4.  Set  the  pans  away  carefully  and  weigh  every  few  days  until  a  nearly 

constant  weight  is  reached. 

5.  At  the  completion  of  the  experiment  carefully  preserve  these  soils  and 

determine  the  amount  of  hygroscopic  moisture  in  them  according  to 
directions  as  given  in  the  following  experiment. 
The  amount  of  capillary  moisture  which  has  disappeared  into  the  air  is  indi- 
cated by  the  loss  in  weight.    Calculate  the  percentage  of  capillary  water, 
using  the  dry  soil  for  the  base. 

Capillary  Moisture 


^\ 

eight  of 
pan 

Weight,  pan 
and  soil 

Dry 

weight 

Dry  weight. 

Loss  in 
weight 

Per  cent  cap- 
illary  water 

Sand { 

Sandy  loam                                                ] 

Loam 

Clay 1 

1 

Muck 

- 

EXERCISE   14  (Continued)  (41) 

QUESTIONS 

1.  Of  what  use  is  capillary  water  for  plant  growth? 

2.  Which  soil  holds  the  most  capillary  water,  and  why? 

3.  Where  does  the  supply  of  capillary  moisture  come  from? 

4.  How  does  it  reach  the  surface  of  the  soil  and  how  is  it  lost? 


Grade. 
Date. . 


(42) 


EXERCISE  15 


Hygroscopic  Moisture 
Purpose. — To  doterminc  tlic  percentage  of  hygroscopic  moisture  in  air  dry 


nh: 


PLAN 


Number  and  weigh  five  evaporating  dishes. 

Into  the  above  dishes  weigh  25  grams  of  each  of  the  five  soils  remaining 
from  tlie  exercise  for  the  determination  of  the  capillary  moisture. 


Fig.  8. — Drying  oven  with  top  tubes  for  thernu 
eter  and  gas  regulator. 


l^_^ 


Fig.  9. — Moisture-proof 
chamber  for  use  in  cooling 
oven-dried  samples  before 
weighing.  IMoisture-ab- 
sorbing  chemicals,  as  strong 
sulfuric  acid,  may  be 
placed  in  the  lower  part  to 
insure  dryness. 


3.  Dry  these  samples  in  an  oven  (Fig.  8)  vrliich  has  a  temperature  slightly 

above  the  boiling  point  of  water. 

4.  Later  cover  the  dishes  and  remove  from  the  oven  and  allow  to  cool  in  a 

dry  chamber  (Fig.  9). 

5.  Weigh  rapidly  and  determine  the  loss  of  moisture. 

6.  Determine  the  per  cent  of  hj'groscopic  moisture  by  dividing  the  weight 

of  moisture  lost  by  the  weight  of  oven  dry  soil. 
If  possible  the  degree  of  humidity  of  the  air  in  the  room  should  be  found  on 
the  day  this  exercise  is  conducted.     If  desired  this  exercise  may  be 
repeated  on  very  dry  and  very  wet  days  to  determine  the  variation  in 
amount  of  hygroscopic  moisture. 


EXERCISE   15   (Continued) 
Amount  of  Hygroscopic  Moisture 


(43) 


Weight  of        Weight,  dish 
dish                  and  soil 

Dry  weight 

Dry  soil  only           Lo-'n 

Per  cent 
hygr.,  water 

Sand 

1 

Sandy  loamj 

1 

Loam ;                      j 

i 

Clay j 

1 

i 

Muck 

! 

QUESTIONS 

1.  Give  a  definition  of  hygroscopic  moisture. 

2.  What  throe  factors  govern  the  amount  of  hygroscopic  moisture  in  the  soil? 

3.  State  two  possible  ways  by  which  this  kind  of  moisture  may  be  beneficial. 


Grade. 
Date. . 


(44) 


EXERCISE  16 


Capillary  Rise  of  Water  in  Soils  of  Different  Texture 
Purpose. — To  determine  the  influence  of  the  fineness  of  a  soil  upon  tlie 
speed  and  total  rise  of  capillary  water. 

plan 
1 .  Close  the  ends  of  the  large  glass  tubes  (Fig.  1 1)  by  mcvans  of  pieces  of  muslin 
firmly  tied  on. 


Fig.  10. — Handy  equipment  to  show 
cf  water  by  capillarity. 


I'lG.  11. — Frame  and  glass  tubes  for  showing  capil- 
lary rise  of  water  in  different  soils. 


12. — Galvanized  tray  or  tank  to  be  used  with  the  support  for  tubes  i 
Also  useful  for  exercise  Xc  17 


showing  capillary  rise  of  water. 


2.  Hold  the  tubes  in  a  vertical  position  and  carefully  fill  with  their  respective 

soils.    After  filling  compact  the  soil  by  allowing  the  tubes  to  drop  from 
a  distance  of  four  inches  four  times  upon  a  book. 

3.  Place  the  tubes  in  a  supporting  frame  (Fig.  11)  over  a  rectangular  pan  of 

water,  so  that  the  ends  are  about  one-half  inch  below  the  surface  of  the 
water  (Fig.  12). 
This  experiment  may  be  set  up  by  the  instructor  but  each  student  must  fill 
out  the  following  observation  blank  for  himself  as  nearly  at  the  time 
indicated  as  possible. 


EXERCISE  16  (Continued) 
Rise  of  Water  at  Different  Periods 


(45) 


8oiI 

i-a  hour 

1  hour 

3  hours 

1  day 

2  days  |  4  days  |  C  days  j  8  days 

1 

1 

2  

1     1 

3 

1         1 

■4 

1 

5 1 

1         1 

6 i 

1 

1 

QUESTIONS 

In  what  soil  does  the  water  rise  the  fastest?    The  highest? 

Can  you  determine  upon  what  factors  the  capillary  rise  of  water  depends? 
Give  several. 

Would  a  moist  condition  of  the  soil  affect  the  total  rise?  Would  it 
affect  the  rate? 

Does  capillary  movement  of  water  take  place  laterally?  In  a  test  of  differ- 
ent fertilizers  on  field  plots  side  by  side,  what  effect  would  this  have? 

What  does  this  experiment  teach  you  concerning  soil  management  and 
plant  growth? 


Grade. 
Date. . 


(46)  EXERCISE  17 

Effect  of  Too  Much  Organic  Matter  on  Rise  of  Water 
The  water  used  by  plants  is  conveyed  to  them  largely  by  means  of  the  process 

called  capillarity. 
Purpose. — To  show  that  certain  farm  practices  may  l)e  harmful,  cutting  off 

the  water  supply  to  plant  roots  by  a  layer  of  organic  matter. 

PLAN  * 

1.  Tie  a  cloth  firmly  over  the  ends  of  two  large  glass  tubes  18  inches  long. 

Fill  to  the  height  of  one  foot  with  fine  soil,  compacted  by  letting  the  tube 
drop  four  times  on  a  book  for  a  distance  of  6  inches  for  every  G  inches 
of  soil  put  in  the  tube. 

2.  In  one  tube  put  about  one  inch  of  cut  straw  or  sawdust;  in  the  other  about 

a  half  inch  of  well  decayed  fine  manure.  Finish  filling  the  tubes  with 
soil.  Place  the  ends  of  the  tubes  in  a  tray  of  water  and  note  the  rise  of 
water. 

3.  In  this  exercise  each  student  must  make  daily  observations  on  the  heights 

of  the  water  in  the  tubes  and  note  the  effect  of  organic  matter  on  the 
rise  of  water. 

Results 

Height  of  wafer 
Soil  w  ith  fine  manure 


Soil  with  cut  straw 


QUESTIONS 

1.  In  which  soil  does  the  water  rise  the  higher  and  why? 

2.  What  is  the  effect  of  plowing  under  poorly  rotted  manure,  straw,  or  a 

heavy  green  crop  in  the  spring? 

3.  What  damage  to  the  ensuing  crop  might  result  if  a  heavy  sod  were  plowed 

under  late  in  the  spring? 

4.  Would  there  be  any  advantage  in  rolling  the  land  directly  after  plowing? 

5.  What  advantage  with  relation  to  organic  matter  does  fall  plowing  have? 


*Adapted  from  Mosier. 


EXERCLSE   17   (Continued)  .  (47) 


Grade 
Date. 


(48) 


EXERCISE  18 
Percolation  of  Water  Through  Soils 


Percolation  is  the  passage  of  water  througii  soils  by  means  of  the  natural 

channels. 
Purpose. — To  study  the  influence  of  texture  and  structure  upon  the  passage 

of  water  through  soils. 


1.  Take  six  soil  tubes  (Fig.  13):    fill  three  of  them  with  the  three  different 
soils  to  within  one-half  inch  of  the  overflow  pipe,  pouring  it  in  looselj\ 


Fig.  13. — Percolation 
soil  tube.  In  comparing 
the  percolation  of  water 
through  several  soils 
the  tubes  are  placed  in 
the  support  block  (Fig. 
14)  and  are  connected 
by  rubber  tubing  at- 
tached to  the  lateral  in- 
lets. A  beakeris  placed 
under  each  drainage 
tube. 


Fig.  H. — .'iuppurt  block  lor  use  in  holding  tubes  with  drainat;f  outlets 


15. — Another  .simple  form  of  apparatus  to  show  percolation  of 
water  through  soils. 


2.  Fill  the  other  three  tubes  with  their  respective  soils,  packing  in  the  usual 

way  by  dropping  or  by  using  the  compacting  machine. 

3.  After  all  the  tubes  are  full  place  a  layer  of  coarse  sand  one-half  inch  deep 

over  the  top  of  each.    This  will  prevent  the  water  as  it  flows  from  dis- 
turbing the  soil  below. 


EXERCISE   18  (Continued) 


(49) 


4.  After  placing  the  tubes  in  the  support  block  (Fig.  14)  connect  the  tubes 

at  the  top  with  rul)ber  tubing  and  place  beaker  glasses  underneath  them 
to  catch  the  water  which  comes  through. 

5.  Record  the  time  elapsing  after  water  is  turned  on  until  it  begins  to  perco- 

late through  each  tube  of  soil. 

6.  Determine  the  quantity  of  water  draining  through  each  soil  in  thirty 

minutes  after  it  begins. 
Note. — This  exercise  could  be  tried  with  five  soils  as  suggested  in  Fig.  15. 


Percolation  of  Water  Through  Soils 

ShtiH 

Loam 

Clay 

Loose     i  Compact 

1 

Loose     1  Compact 

Loose 

Compact 

Minutes  for  percolation  to  begin 

, 

Amount  of  water  percolating  in 

' 

QUESTIONS 


Upon  what  two  main  factors  does  percolation  depend? 

Would  water  percolate  faster  through  soil  which  was  dry  at  first  or  through 

wet  soil?    Why? 
What  conditions  in  the  soil  assist  percolation? 


4.  Is  a  sandy  soil  objectionable  when  percolation  is  considered? 

5.  What  does  this  experiment  indicate  concerning  the  depth  of  plowing? 

6.  Would  growing  crops  be  benefited   by  a  loose  condition  of   the  surface 

soil? 

7.  Would  there  be  any  advantage  in  fall  plowing?    Why? 

8.  Why  are  clay  soils  often  wet? 

9.  What  does  this  experiment  indicate  concerning  the  comparative  depth 

at  which  tile  drains  should  be  put  in  a  clay  soil  and  in  a  sandj'  soil? 


(60)  EXERCISE   18   (Continued) 


Date. 


EXERCISE  19 


(51) 


Clod  Formation 
Purpose. — To  study  the  clod-forming  properties  in  soils  of  different  kinds. 

PLAN 

1.  Take  small  samples  of  each  of  the  available  soils  of  the  region;  include  a 

sample  of  heavy  clay  soil;  also  include  one  mixture  of  sand  with  clay  and 
one  of  humus  and  clay. 

2.  On  a  mixing  board  mix  each  with  enough  water  to  make  as  stiff  a  "putty" 

as  each  sample  will  make.    Roll  part  of  it  into  the  form  of  an  inch  marble, 
and  another  part  into  a  half-inch  cylinder  about  four  inches  long. 

3.  Make  up  all  the  samples  as  nearly  alike  as  possible.    Label  each  by  stippling 

a  number  on  each  kind.    Put  the  molded  samples  into  cigar  boxes  or  on 
shelves  to  dry  for  several  days. 

4.  Make  studies  of  the  relative  breaking  powers  of  these  samples,  and  make 

a  record  of  their  clod-forming  properties. 

Clod  Formation 


Kind  of  soil 

No. 

Crushing  strength 
of  marbles 

Breaking  strength 
of  sticks 

Remarks 

1 

j        ! 

1        1 

1        i             1 

Note. — If  instruments  are  not  available  for  measuring,  crushing  and  breaking  strength, 
comparisons  may  be  made  after  breakinia;  with  fingers. 


QUESTIONS 

1.  Make  a  list  of  the  samples  in  order — the  hardest  clods  first. 

2.  What  interest  has  the  farmer  in  the  clod-forming  properties  of  field  soils? 

3.  Which  soils  must  be  handled  most  carefully  after  rains? 

•i.  Which  are  likely  to  form  hard  crusts  during  dry  weather  if  improperly 

managed? 
o.  Which  soils  will  work  up  into  the  most  perfect  seed  beds  for  gardens? 
().  Why  should  clay  soils,  if  plowed  rather  wet,  not  he  allowed  to  dry  l^efore 

harrowing? 
7.  Give  other  points  in  the  proper  management  of  clod-forming  soils. 


(52)  EXERCISE   19   (Continued) 


uraae. 
Date. . 


EXERCISE  20 


(53) 


Soil  Surface  and  Percolation 

Purpose. — To  study  the  relationship  between  soil  surface  and  the  percolation 
of  free  water. 

PLAN 

1.  Secure  three  or  more  small   glass  tubes  of   uniform  length  (about  one 

foot)  and  place  them  in  a  jar  of  water  deep  enough 
to  fill  them  to  the  top.  Place  the  finger  or  palm  of 
the  hand  against  the  top  of  the  tubes  and  with  the 
other  hand  remove  the  bundle  of  tubes  from  the 
jar  of  water.  Hold  the  bundle  in  a  vertical  position 
and  note  that  the  water  remains  in  the  tubes.  Now 
remove  the  hand  from  the  top  and  see  how  quickly 
the  water  descends. 

2.  Fill  two  soil   tul)es  (Fig.  16)  with  clay  loam,  packing 

them  alike.  Set  them  in  a  jar  of  water  until  satu- 
rated. Loosen  the  surface  of  one  with  a  kitchen  fork; 
smooth  the  surface  of  the  other  with  the  bowl  of  a 
wet  spoon  to  avoid  the  free  entrance  of  air.  Then  set 
the  tubes  of  soil  so  as  to  drain  into  beaker  glasses.  ^"^"^1 

Compare  the   rates   of    drainage  of   free  water  from  * 

the  two  tubes  as  a  result  of  the  difference  in  treat-  soiftui>e!2''^^2™wi'th 

perforated  bottom,  use- 
ful in  many  exercises. 


ment  of  the  surfaces^ 


Surface  smooth 

Surface  stirred 

Amount  of  water  in  1  hour 

Amount  of  water  in  2  days 

QUESTIONS 

1.  Why  does  the  exclusion  of  air  at  the  top  of  the  tubes  retard  percolation? 

2.  Does  a  heavy  soil  beaten  by  rain  or  puddled  by  free  water  stantling  on 

the  surface  tend  to  exclude  the  air?    Explain. 

3.  What  treatment  can  be  given  to  the  surface  of  field  soils  after  heavy  rains 

before  they  are  quite  dry  enough  to  plow  well? 

4.  Does  a  heavy,  thick,  dry,  crust  tend  to  exclude  air  from  the  soil  more  than 

a  loosened  surface?     Explain. 

5.  Would  harrowing  tend  to  let  the  free  water  downward?    Whv? 


(^4)  EXERCISE  20  (Continued) 

6.  When  air  is  admitted  to  the  soil  in  very  early  spring,  what  effect  does  it 

have  upon  the  soil  temperature?    Explain. 

7.  In  early  spring  is  it  better  to  allow  the  surplus  water  to  percolate  downward 

into  the  soil  or  to  wait  for  it  to  evaporate  from  the  surface?    Give  reasons 

8.  If  free  water  is  caused  to  percolate  below  the  depth  of  tillage  in  spring' 

what  benefit  may  it  have  upon  crops  during  subsequent  dry  weather?    ' 


Date 

EXERCISE  21  (55) 

Capacity  of  Loose  and  Compact  Soils  to  Hold  Water 

Purpose. — To  study  the  influence  of  the  texture  and  structure  of  different 
soils  upon  their  capacity  to  retain  water. 


Use  four  soils — sand,  loam,  clay,  and  muck. 

1.  Select  eight  soil  cj'linders  (Fig.  16)  and  place  a  circular  piece  of  filter 

paper  in  the  bottom  of  each.    Number  and  weigh  each  cylinder  carefully. 

2.  Fill  the  first  four  tubes  to  within  exactly  one  inch  of  the  top,  pouring  the 

soil  in  gentl}'  so  that  it  will  rest  in  the  tube  in  a  very  loose  condition. 

3.  Fill  the  second  lot  of  tubes  to  within  one  inch  of  the  top  and  pack  uniformly 

by  the  dropping  method  or  by  means  of  the  compacting  machine. 

4.  Weigh  and  record  weights  of  filled  tubes. 

5.  Place  the  tubes  in  a  galvanized  iron  tank  and  pour  water  around  them 

until  it  reaches  the  height  of  the  surface  of  the  soil,  thus  allowing  the 
water  to  percolate  up  through. 

6.  Let  stand  until  moisture  appears  at  surface  of  soil  in  each  cylinder,  noting 

time  required  for  water  to  come  up  through. 

7.  Finally  remove  the  tubes  from  the  tank  and,  after  wiping  off  all  free  water 

with  a  cloth,  weigh  immediately  upon  balances. 

8.  Place  cylinders  in  racks  where  the  water  maj^  be  allowed  to  percolate  out, 

and  cover  top  with  a  glass  plate  to  prevent  evaporation. 

9.  Weigh  the  cylinders  according  to  the  time  indicated  in  the  table. 


(oti) 


EXERCISE  21   (Continued) 
Water  Holding  Power  of  Soils 


Loose 

Compact 

Sand 

Loam 

Clay 

Muck 

Sand 

Loam        Clay 

Muck 

Number  of  tube  .                ... 

il 

Weight  of  tube 

Weight,  tube  and  soil 

j 

, 

Time  for  top  to  become  moist 

I 

Depth,  dry  soil  .                 .... 

: 

Depth  wet  soil  . 

1 

Moist  weight,  tube  and  soil . . . 

Weight  of  moist  soil 

! 

Water  taken  up,  per  cent .... 

Grs.  water  lost,  1  hour 

Grs.  water  lost,  2  days 

Grs.  water  lost,  4  days 

Grs.  water  lost,  6  days 

. 

j 

Total  water  lost,  per  cent .... 

i 

\ 

Acre  inches  water  retained .... 

! 

1 

i 

QUESTIONS 

1.  When  a  soil  is  saturated  does  it  contain  both  free  water  and  capillary 

water?    Give  reasons  for  your  answer, 

2.  What  per  cent  of  water  was  found  in  each  of  the  soils  Avhen  saturated? 

3.  What  relation  does  this  proportion  bear  to  the  pore  space  of  the  soil? 

4.  What  did  you  observe  concerning  the  expansion  of  a  muck  soil  when  wet? 

What  does  this  show  concerning  the  depths  at  which  tile  drains  should 
be  placed? 


EXERCISE  21   (Continued)  ^       (57) 

5.  From  the  results  secured,  what  type  of  soil  would  you  say  would  be  most 

benefited  by  cultivation? 

6.  Which  soils  would  leach  most? 

7.  What  effect  does  rolling  have  upon  soil  moisture? 

8.  What  effect  does  fall  plowing  or  early  spring  plowing  have  upon  soil 

moisture? 

9.  Define  gravitational  water.    What  are  its  uses  and  when  is  it  injurious? 


Grade. 
Date. . 


(58)  EXERCISE  22 

Effect  of  Evaporation  on  Soil  Temperature 
Purpose. — To  show  that  soils  are  cooled  when  water  evaporates  from  them. 

PLAN 

1.  Take  two  dairy  thermometers  which  agree  in  their  reading.     Tie  a  few 

inches  of  cloth  around  the  bulb  of  one  thermometer  and  suspend  the 
lower  part  of  the  cloth  in  a  glass  of  water  that  is  slightly  warmer  than 
the  room. 

2.  From  time  to  time  note  the  difference  in  readings  of  the  two  thermometers, 

and  decide  how  much  difference  is  produced  by  evaporation  of  water 
from  the  cloth. 

QUESTIONS 

1.  Show  the  analogy  between  this  exercise  and  the  evaporation  of  water  from 

soils. 

2.  Would  soils  be  kept  cold  by  water  evaporating  from  them  in  the  spring 

of  the  year? 

3.  How  many  units  of  heat  are  absorbed  or  dissipated  by  the  evaporation 

of  one  unit  of  water  (see  any  text-book  on  physics). 

4.  Why  should  farmers  wishing  to  warm  their  soils  in  early  spring,  prevent 

the  evaporation  of  water  from  them?    Would  harrowing  do  this? 

5.  If  harrowing  produces  a  dust  mulch  and  checks  evaporation,  would  the 

free  water  below  the  surface  be  held  there  or  tend  to  find  its  way  do\A-n- 
ward? 

6.  Would  the  loosening  of  the  surface  crust  of  the  soil  tend  to  check  do^^^l- 

ward  percolation  of  soil  water  or  increase  it? 

7.  Would  the  loosening  of  the  soil  crust  increase  or  retard  the  entrance  of 

warm  spring  air? 


EXERCISE  22  (Continued)  (^^ 


Grade. 
Date. . 


(60) 


EXERCISE  23 


Value  of  Mulches  in  the  Retention  of  Moisture 
Purpose. — To  determine  the  loss  of  water  from  the  surface  of  a  soil  by 
evaporation  and  the  value  of  various  mulches  in  preventing  this  loss. 
A  mulch  is  any  material  placed  or  created  on 
the  surface  of  a  soil  to  prevent  evapora- 
tion.    It  may  be  composed  of  loose  soil 
or  it  may  be  artificial  material,  such  as 
leaves,  straw,  etc. 

PLAN 

1.  The  cylinders  (Fig.  17)  will  be  filled  with 

loam  soil  in  a  moist  condition. 

2.  Treat  the  surface  of  the  soil  in  each  tube 

according  to  the  table.  The  artificial 
mulch  should  be  3  inches  deep  in  all 
cases.  Fill  the  outside  jacket  of  the  cyl- 
inder with  water. 

3.  Weigh  each  cylinder  daily  and  calculate 

the  loss   of   water.    Replace    the  water  which  has  been  lost  by  evap- 
oration. 

Value  of  Mulches 


Fig.  17. — A  good  form  of  cylinder  for 
mulch  experiments.  Water  may  be  added 
from  time  to  time  by  the  side  tube. 


Bare 
soil 

Coarse 
sand 

Clay 

Fine 
sand- 
loam' 

Cut 
straw 

Cultivated 

1  in. 
deep 

2  in. 
deep 

.3  in. 
deep 

4  in. 
deep 

"Weight  of  tubes 

Lot?"?    1  dav 

! 

1 

Loss,  3  days 

1        !        i        ! 

Loss,  4  days 

1 

1            i 

Loss  5  days 

! 

1 

'  - 

Loss,  6  days 

1 

1 

Loss,  2  weeks 

Total  loss,   tons,   per 
acre,  per  week 

EXERCISE  23  (Continued)  (61) 

QUESTIONS 

1.  What  is  the  average  annual  rainfall  for  the  country  in  which  you  live? 

2.  How  man}'  inches  of  water  are  used  by  a  (a)  400  bushel  crop  of  potatoes, 

(6)  100  bushels  of  corn,  (c)  3.5  tons  of  hay? 

3.  How  many  inches  of  water  may  be  lost  by  evaporation  from  a  bare  soil? 

4.  Which  artificial  mulch  is  the  most  efficient  and  which  is  the  least  efficient? 

5.  How  does  a  mulch  prevent  loss  of  water  by  evaporation? 

6.  Which  is  the  more  economical,  a  natural  or  an  artificial  mulch? 

7.  Which  mulch  would  need  renewal  the  more  often,  clay  or  sandj'  loam, 

and  wh}'? 

8.  Wh}'  should  cultivation  always  be  done  soon  after  a  beating  rain? 

9.  What  is  the  best  depth  for  cultivation?    Why? 

10.  What  effect  will  cultivation  have  on  a  very  wet  soil? 

11.  What  effect  do  you  think  mulches  would  have  upon  the  temperature  of 

a  soil? 

12.  What  effect  would  scattering  a  light  coating  of  manure  upon  meadows 

have  upon  the  grass  plants  during  hot,  dry  weather? 

13.  What  influence  does  rolling  have  upon  the  evaporation  of  water  from 

soil? 

14.  What  can  you  say  about  the  use  of  corrugated  rollers? 


(62)  EXERCISE  '23   (Continued) 


Grade. 
Date. . 


EXERCISE  24  (63) 

Optimum  and  Critical  ]\Ioisture 

Purpose. — To  determine  optimum  and  critical  moisture  content  and  amount 

of  available  moisture  in  different  soils. 
Optimum  moisture  content  is  that  amount  of  water  in  the  soil  with  which  a 

plant  is  able  to  make  its  best  growth. 
Critical  moisture  content  is  the  minimum  amount  of  water  with  which  a  plant 

is  aljle  to  survive. 

PLAN 

1.  Take  five  one-gallon  glass  battery  jars  (or  tin  cans)  having  a  small  hole 

close  to  the  bottom.  Into  the  hole  fit  a  drain  tube  made  of  glass  tubing 
with  a  glass-wool  filter  at  the  inner  end,  so  that  it  will  take  licjuid  from 
the  lowest  place  in  the  jar. 

2.  Weigh  each  jar  and  record  weight. 

3.  Fill  each  jar  to  within  one  inch  of  the  top  with  soil  compacted  to  a  moder- 

ate degree.    Use  the  sand,  sandy  loam,  loam,  clay  and  muck. 

4.  Pour  the  soil  out  and  mix  with  water  until  the  soil  is  in  the  best  possible 

field  condition.  Keep  careful  record  of  the  amount  of  water  added  to 
each  soil. 

5.  Fill  the  jars  with  the  moist  soil  and  weigh. 

6.  Plant  five  kernels  of  corn  three-fourths  of  an  inch  deep  in  each  jar. 

7.  Cover  the  tops  of  the  jars  with  oilcloth  or  waxed  paper  to  prevent  evapora- 

tion until  the  com  is  up. 

8.  Water  them  at  intervals  when  necessary,  adding  enough  water  so  that  a 

drop  or  two  will  be  forced  out  at  the  drain.  Always  add  the  same  amount 
of  water  to  each  pot. 

9.  When  the  corn  is  a  foot  high,  cease  watering  antl  record  the  number  of 

days  before  the  plants  commence  to  wilt. 
10.  Then  empty  the  pots  and  determine  the  amount  of  capillary  moisture 
in  each  soil. 


(64) 


EXERCISE  24  (Continued) 
Opiimum  and  Critical  Moisture  for  Corn 


Sand 

Sandy 
loam 

Loam 

Clay 

Muck 

W  eight  of  jar                                 

' 

Amount  of  water 

1                    1 

Weight  filled  jar 

Per  cent  of  water 

TViimhpr  nf  rlnv«;  to  wilt                  

1 

1 

Per  cent  of  moisture  in  soil  at  wilting    . . 

QUESTIONS 

1.  Which  of  the  soils  has  the  largest  amount  of  available  moisture? 

2.  Which  soil  will  store  up  the  largest  amount  of  moisture? 

3.  If  each  soil  should  have  the  same  amount  of  water  to  commence  with,  on 

which  would  the  crops  wilt  the  quickest? 

4.  What  is  the  water  content  of  green  alfalfa,  corn,  turnips,  and  potatoes? 

Of  straw,  hay,  ensilage,  and  shelled  corn? 


EXERCISE  24  (Continued)  (65) 


Grade 
Date. 


(66) 


EXERCISE  2,'^ 


Drainage  and  Soil  Temperature 
Purpose.— To  show  the  influence  of  stancUng  water  in  a  soil  upon  its  tem- 
perature. 

PLAN  * 

1.  Prepare  two  similar  vessels — one  water  tight  and  the  other  with  holes  to 

allow  of  good  drainage  at  the  bottom;  these  may  be  two  tubs  or  boxes. 
Fill  them  with  the  same  kind  of  soil  to  a  depth  of  six  inches. 

2.  Plant  an  equal  number  of  grains  of  corn  in  each  box. 

3.  Sprinkle  equal  quantities  of  water  upon  each  vessel  until  it  begins  to  drain 

from  the  box  with  the  perforated  bottom.     Repeat  this  as  often  as  is 
necessary  until  the  corn  is  well  up. 

4.  After  ten  or  twelve  days  insert  the  thermometers  and  determine  hourly 

the  temperature  of  each  at  1,  2  and  4  inches  in  depth. 

Results 


Time 

1  inch  deep 

2  inches  deep 

4  inches  deep 

Drained 

L'ndrained 

Drained          Undrained 

Drained          Undrained 

9  o'clock.     .. 

11  o'clock 

1 

1  o'clock 

1                           1 
i 

3  o'clock    .        . 

1 

i                           i 

5  o'clock    ...    . 

1 

Date  of  recording  thermometer  readings 

No.  of  plants  on  drained  soil On  undrained  soil . 


QUESTIONS 

Why  is  there  a  difference  in  temperature? 
Why  are  clay  soils  often  cold  or  colder  than  sandy  soils? 
Why  does  corn  often  rot  in  the  ground  during  a  wet  spring? 
Name  some  of  the  benefits  of  drainage  to  the  farmer. 
What  is  the  difference  between  natural  drainage  and  artificial  drainage? 
Why  is  the  latter  necessary  and  what  is  the  most  successful  method  of 
carrying  it  out? 


"Adapted  from  Mosier. 


EXERCISE  25  (Continued)  (67) 


Grade. 
Date. 


(68) 


EXERCISE  26 


Color  and  Temperature 
Purpose. — To  determine  the  effect  of  color  of  soil  on  temperature. 
The  temperature  of  the  soil  influences  indirectly  the  yield  per  acre. 


1.  Secure  four  wooden  boxes  approximately  12  inches  square  by  eight  inches 

deep.    Bore  holes  in  the  bottom  for  proper  drainage.    Fill  with  a  uniform 
lot  of  loam  soil  to  within  one-half  inch  of  the  top. 

2.  Plant  corn  in  one-half  of  one  box  at  a  uniform  depth  and  a  like  numl^er 

of  kernels  in  the  other  half. 

3.  Cover  the  one-half  of  the  soil  with  chalk  dust  or  white  sand  and  the  other 

with  lamp  black  or  very  dark  humus  soil.    Be  careful  that  the  depth  of 
the  seed  is  the  same  after  these  covers  are  put  over  the  soil. 

4.  In  each  of  the  other  boxes  plant  equal  numl^ers  of  wheat,  beans  and  buck- 

wheat.   Use  the  same  light  and  dark  covering  as  in  (3). 

5.  Moisten  all  the  soil  equally  from  time  to  time. 

6.  Place  the  boxes  where  the  sun  will  reach  all  the  soil  surfaces  equally. 

7.  Record  in  the  table  the  number  of  plants  up,  in  each  half  box  twice  a  day. 

Number  of  Plants  up  Each  Morning  and  Evening 


Number 
of  days 

Light  soil 

Dark  Soil 

Corn            Wheat 

( 

Beans 

Buck- 
wheat 

Corn 

Wheat 

Beans           Buck- 
wheat 

A.  M 

1 

1 

P.  M 

i 

Select  a  clear  day  and  make  observations  on  the  temperature  of  each  half 
of  one  box.  Insert  a  thermometer  one-half  inch,  and  another  four 
inches  deep,  also  place  one  two  inches  above  the  surface.  Take  readings 
every  two  hours  and  record  in  the  temperature  table. 

Each  student  should  make  observations  on  all  plots  and  keep  results  in 
tabular  form. 

*  Adapted  from  M  osier. 


EXERCISE  26  (Continued) 
Record  of  Temperature — Thermometer  Readings 


(69) 


Location 
of  thermometer 


Temperatures 


11   A.  M.  1    p.  M. 


Light  soil 

2  inches  above.  .  .  . 

H  inch  in  soil ..... 

4  inches  in  soil .... 

1 

Dark  soil 
2  inches  above.  .  .  . 

1 
Yz  inch  in  soil 

4  inches  in  soil .... 

QUESTIONS 

1.  Explain  why  one  soil  is  heated  more  than  the  other. 

2.  What  effect  does  organic  matter  have  on  the  color  of  soil?    Why? 

3.  On  which  soil  do  the  plants  ^appear  quickest? 

4.  Which  kind  of  plants  show  first? 

5.  Give  in  their  proper  order  the  general  dates  for  planting  winter  wheat^ 

spring  wheat,  corn,  mangels,  cabbages,  oats,  potatoes,  barley,  alfalfa, 
clover,  beans  and  other  field  and  garden  seeds.  State  the  temperature 
at  which  each  of  these  plants  germinates  the  best. 

6.  Name  six  conditions  which  influence  soil  temperature. 

7.  What  effect  has  (a)  rolling,  and  {h)  harrowing  upon  the  temperature  of 

the  soil? 

8.  Show  by  means  of  a  diagram  how  the  slope  of  the  land  may  influence  the 

temperature. 


(70)  EXERCISE  26   (Continued) 


Grade. 
Date. . 


EXERCISE  27  (71) 


Soil  Ventilation 

Purpose. — To  demonstrate  the  practical  importance  of  soil  ventilation  and 
drainage,  and  to  call  attention  to  the  manner  in  which  the  soil  ventilation 
may  be  affected  by  the  structure  of  the  soil. 

PLAN* 

1.  Secure  four  round  pans  about  8  inches  deep.     (Gallon  cans  will  do.) 

2.  Fill  two  of  the  pans  to  within  one  and  one-half  inches  of  the  top  with 

loose  clay  soil  which  has  a  good  field  condition  of  moisture.  Then  plant 
twenty  grains  of  com  in  each  pan  by  laying  the  corn  on  the  surface  of 
the  soil  and  placing  an  inch  of  soil  over  the  grains. 

3.  Fill  the  third  pan  to  the  same  height  with  the  same  kind  of  soil  in  a  very 

compact  condition.  Plant  twenty  grains  of  corn  in  the  same  manner 
as  before,  except  compact  the  soil  over  the  grains.  Prepare  soil  for  Nos. 
1  and  3  together. 

4.  Avoid  puddling  by  giving  plenty  of  time  for  diffusion  of  water.     Great 

care  is  necessary  to  secure  the  right  moisture  conditions. 

5.  Make  a  germinating  pan  of  the  fourth  by  filling  it  half  full  of  sand.    Place 

twenty  grains  of  corn  on  the  sand  and  cover  with  moist  filter  paper. 

6.  Keep  the  pan  moistened  as  showTi  in  table  and  cover  with  oilcloth  or  waxed 

paper  until  seedlings  are  well  up. 

7.  See  that  the  different  pans  are  kept  under  the  proper  moisture  conditions. 

8.  Observe  the  rate  and  percentage  of  germination  each  day  in  the  shallow 

pan. 

9.  At  the  end  of  ten  days  examine  the  pans  closely  and  make  the  following 

observations. 

Ventilation  and  Germination 


No.  of                Treatment  of  soil               Pe^  cent  of 
pan                                                             ]  germination 

Strenuth  of     Appearance 
growth          of  seedings 

Remarks 

1 

2 

Loose,  wet 

3 1  Compact,  moist 

4 

Germination  pan,  moist                      i 

♦Adapted  from  Department  of  Soil  Technology,  Cornell  University. 


(72)  EXERCISE  27  (Continued) 

QUESTIONS 

1.  What  is  soil  ventilation? 

2.  What  is  the  effect  of  compacting  the  soil  on  the  germination  of  the  seeds? 

3.  What  effect  did  the  wet  condition  of  the  soil  have  on  the  germination  and 

growth? 

4.  Is  either  compactness  or  excess  of  water  likely  to  occur  in  sandy  soil? 

5.  What  would  be  the  effect  of  tile  drainage  on  soil  aeration  in  a  heavy  clay 

soil? 

6.  Name  the  different  forces  which  serve  to  change  the  air  in  the  soil. 

7.  Of  what  importance  is  ventilation  to  the  bacteria  which  live  on  clover 

and  alfalfa  roots? 

8.  What  relation  has  ventilation  to  the  decay  of  organic  matter  in  the  soil? 

9.  State  clearly  why  soil  ventilation  is  important. 


EXERCISE  27   (Continded)  (73) 


Grade. 
Date. . 


(74) 


EXERCISE  28 


Amount  of  Organic  Matter  in  Soils 

Purpose. — To  compare  roughly  the  relative  amounts  of  organic  matter  in 
two  different  samples  of  field  soils. 


1.  Place  a  small  amount  of  each  soil  in  an  evaporating  dish  and  heat  for 

several  hours  in  an  oven  in  order  to  drive  off  hygroscopic  moisture. 

2.  Number  and  carefully  weigh  on  sensitive  balances  two  or  more  crucibles 

with  covers. 

3.  Place  in  each  crucible  ten  grams  of  the  previously  dried  soil  and  ignite 

at  a  glowing  temperature  for  an  hour.    Lift  the  cover  occasionally  to  allow 
gases  to  escape. 

4.  After  the  samples  have  been  cooled  in  a  closed  chamber,  weigh  again  and 

determine  the  loss  of  each. 

5.  The  loss  in  weight  of  each  sample  is  largely  due  to  the  burning  away  of 

the  organic  matter.    A  part  of  the  loss  is  due,  however,  to  the  escape  of 
water,  of  crystallization,  etc. 

6.  Students  having  time  for  extra  laboratory  practice  should  test  other 

samples  for  organic  matter. 

Results 


Weight,  crucible  and  soil 


Weight 
crucible 


Before  ignition 


After  ignition 


Lo.ss,  per  cent 


QUESTIONS 

1.  Do  uplands  or  lowlands  usually  contain  the  most  organic  matter?    Wh}^? 

2.  Is  the  percentage  of  organic  matter  present  in  any  soil  a  good  indication 

of  its  fertility? 

3.  Do  soils  containing  much  organic  matter  plow  easier  or  harder  than  others? 

4.  What  is  meant  by  active  and  inactive  organic  matter  and  what  is  their 

relative  importance?    Give  examples  of  each. 


EXERCISE  2S  (CoxTiNUKD)  (75) 

5.  What  is  humus  and  how  does  it  ditt'er  from  organic  matter? 

6.  How  much  organic  matter  is  there  in  an  acre  of  normal  soil? 

7.  Give  six  of  the  most  important  benefits  of  organic  matter. 

8.  Show  clearly  how  the  supply  of  organic  matter  may  be  maintained  in 

different  types  of  farming. 


Grade. 
Date. . 


(76) 


EXERCISE  29 


Absorption  of  Plant  Food  by  Soils 
Purpose. — To  show  the  power  of  soils  to  absorb  solu})le  food  materials  and 
humus  and  the  influence  of  lime  on  this  process. 


Place  six  glass  or  metal  percolators  in  the  rack  in  their  proper  order.    Fold 
small  pieces  of  filter  paper  to  be  carefully  inserted  in  the  base  of  each 
percolator. 
Fill  the  percolators  with  soil  as  follows: 
No  1.  400  grams  of  clay  loam. 
No.  2.  400  grams  of  clay  loam. 
No.  3.  400  grams  of  clay  loam  with  which  there   has   been  mixed  5 

grams  of  lime. 
No.  4.  400  grams  of  sandy  loam. 
No.  5.  400  grams  of  sandy  loam. 

No.  6.  400  grams  sandy  loam  with  which  there  has  been  thoroughly 
mixed  5  grams  of  lime. 
Add  the  following  solutions  to  the  designated  portions  of  soil: 
Funnels  Nos.  1,  3,  4  and  6  —  300  cc.  of  manure  extract. 
Funnels  Nos.  2  and  5  —  300  cc.  of  potassium  permanganate  solution. 
Note  carefully  the  rate  of  passage  of  the  liquid  through  different  portions 
of  the  soil.    Collect  and  examine  the  first  five  cc.  of  solution  that  passes 
through  the  stem  of  each  funnel,  comparing  its  color  with  subsequent 
portions  of  the  original  liquid,  and  the  different  treatments  one  with 

Ahsorption  of  Plant  Food  by  Soils 


Kind  of 
soil 

Lime 
treatment 

Solution 
treatment 

Time  re- 
quired 
for    1st 
drop 

Color  of 
1st  por- 
tion of 
perco- 
late 

Color  of 
latter 
portion 
of  perco- 
late 

Reac- 
tion, 
litmus 

Remarks 

No  lime 

Manure  extract 

Clay  loam 

No  lime 

Permanganate 

1 

Limed 

Manure  extract 

No  lime 

Manure  extract 

Sandy  loam 

No  lime 

Permanganate 

Limed 

Manure  extract 

"Adapted  from  Department  of  Soil  Technology,  Cornell  University. 


EXERCISE  29   (Continued)  (77) 

QUESTIONS 

1.  What  is  absorption? 

2.  How  is  the  manure  extract  affoctetl  in  passing  through  tiio  soil? 

3.  How  does  lime  affect  the  process? 

4.  What  is  leaching? 

5.  What  kind  of  soil  would  lose  most  l)y  leaching? 

6.  Would  you  follow  the  same  method  for  applying  nitrate  of  soda  on  a  sandy 

soil  as  on  a  clay  soil?    Why? 

7.  Which  of  the  above  two  soils  would  l)e  i)est  plowed  in  the  Fall?    Why? 

8.  What  does  this  experiment  teach  us? 


Grade. 
Date. . 


(78)  EXERCISE  30 

Testing  Soils  for  Acidity 

Purpose. — There  are  three  common  tests  for  soil  acidity.  Any  one  of  these 
should  furnish  fair  evidence  as  to  the  need  of  the  soil  for  lime.  An  agree- 
ment of  the  three  tests  should  furnish  conclusive  evidence  regarding  the 
condition  of  the  soil.  The  purpose  of  this  exercise  is  to  familiarize  the 
student  with  the  manipulation  of  these  tests. 


Samples  of  the  surface  soil  and  subsoil  of  a  soil  well  stocked  with  lime  and 
samples  of  acid  soils  should  be  supplied.  Acid  phosphate,  lime,  fresh 
muck,  wood  ashes,  silage,  and  horse  manure  also  may  be  tested. 

I.  Litmus  Paper  Test. — Take  a  tumbler  with  a  smooth  bottom.     By  means 

of  forceps  or  the  tips  of  the  fingers  select  two  pieces  of  litmus  paper,  one 
blue  and  the  other  neutral,  and  drop  into  the  tumbler.  Then  cut  a  disk 
of  filter  paper  and  place  in  the  bottom  of  the  tumbler  over  the  litmus 
paper.  On  top  of  this  place  two  or  three  tablespoonfuls  of  the  moist 
soil  to  be  tested.  If  the  soil  is  not  moist  enough  add  a  small  amount  of 
rain  or  distilled  water.  Take  a  handful  of  the  same  soil  and  squeeze  into 
a  ball.  Break  the  ball  and  in  the  center  insert  a  piece  of  blue  litmus 
paper.  With  both  of  these  tests,  if  the  soil  is  acid,  the  litmus  paper  should 
show  a  decided  pink. 

II.  Ammonia  Test. — Take  two  tumblers  and  fill  each  about  three-quarters 

full  of  distilled  or  rain  water.  To  the  first  add  a  few  drops  of  common 
ammonia.  Then  into  each  tumbler  stir  a  tablespoonful  of  the  soil  to 
be  tested,  being  careful  to  use  two  spoons  and  keep  each  in  its  respec- 
tive glass.  Stir  the  contents  of  each  glass  thoroughly  for  three  or  four 
minutes  and  set  aside  for  a  few  hours.  At  the  end  of  that  time  examine 
the  contents  of  each  glass.  If  the  soil  needs  lime  the  water  standing 
above  the  soil  in  the  glass  in  Avhich  the  ammonia  has  been  added  will 
have  a  dark,  reddish-brown  or  black  appearance,  while  the  water  in 
the  other  glass  will  be  very  nearly  clear.  On  the  other  hand,  if  the  soil 
is  well  stocked  with  carbonates  of  lime  or  magnesia,  the  soil  water 
in  both  glasses  will  be  entirely  clear. 

III.  Hydrochloric  Acid  Test. — Place  a  small  quantity  of  soil  in  an  evaporating 
dish  and  pour  on  this  three  or  four  drops  of  hydrochloric  acid.  If  bubbles 
escape  it  is  a  sign  that  there  is  an  abundance  of  carbonates.  If  there 
is  no  effervescence  the  soil  lacks  carbonates  and  is  probably  acid. 


EXERCISE  30  (Continued) 
Color  or  Action  of  Indicator 


(79) 


Name  of  test 

Surface  s-oil 

Subsoil 

Surface  soil        ' 
2 

Subsoil 
2 

Litmus  i)ai)er  (tumbler) 

Litmus  paper  (bull)   . . 

Check 

Acid 1 

QUESTIONS 

What  effect  have  the  moist  fingers  upon  litmus  paper? 

Write  the  reaction  which  occurs  when  carbonate  of  lime  or  other  bases 

in  the  soil  are  acted  upon  by  hydrochloric  acid. 
Why  does  the  washing  of  an  acid  soil  in  the  presence  of  ammonia  have  a 

brown  color? 
Why  is  it  necessary  to  test  the  subsoil  as  well  as  the  surface  soil? 


CJrado 
Date. 


(80) 


EXERCISE  31 


Examination  of  Chemical  Fertilizers 
Fill  a  column  as  nearly  as  possible  for  each  sample  of  fertilizer  examined. 


Sample  1 

Sample  2 

Sample  3 

Sample  4 

Fertilizer 

Source 

Amount  of:  Nitrogen. 

Phosphoric  acid 

Potash 

Lime 

Color 

1 

Smell 

Taste 

Crystal,  powder,  etc. 

Deliquescent 

! 

T\ppn  well                          .  . 

Availability: 

Immediately 

! 

Quickly 

Slowly    

! 

Very  slowly  

1 

Cost  per  ton 

i 

Value  per  lb.  of: 

Phosphoric  acid 

Potash 

EXERCISE  31   (Continued)  (81) 

QUESTIONS 

1.  How  would  you  distinguish  nitrate  of  soda  from  muriate  of  potash? 

2.  How  does  rock  phosphate  differ  from  acid  phosphate? 

3.  Is  the  phosphoric  acid  in  dissolved  bones  more  available  than  in  acid 

phosphate? 

4.  How  does  dried  blood  differ  from  tankage? 

5.  What  is  the  use  of  peat  or  muck  in  mixed  fertilizers  and  what  is  its  fertility 

value? 

6.  Is  lime  a  good  material  to  use  with  mixed  fertilizer  and  why? 


Grade 
Date. 


(82) 


EXERCISE  32 


Study  of  Plowing 
"  The  art  of  agriculture  will  never  rise  higher  than  the  man  who  manages  the  land." 
Plowing  is  the  oldest,  the  most  fundamental  and  far-reaching  operation  in 
soil  management.  In  perhaps  no  other  farm  operation  is  the  character 
and  skill  of  a  man  reflected  so  strongly  as  in  the  furrow  which  he  turns 
with  his  plow.  The  freshly  turned  earth,  as  well  as  his  horses  and  plow, 
are  all  silent  witnesses  (Fig.  18). 


Fig.    is.  — PrcioniiLT  l,iin<.-lf  f-,    n  -  al-pl-uiiiL' 

SCORE    CARD    FOR   PLOWING 


1 

Perfect 
Score 

20     i 

15 

Proper  inversion  of  furrow  slice 

15 

Soil  properly  pulverized 

5     j               i 

Furrow  of  uniform  width 

10 

1 

Furrow  of  uniform  depth 

15 

Trash  covered                                     10 

1            ! 

1 

..   5 

Handling  team 

5 

Total                 

100 

EXERCISE  32  (Continued) 


(83) 


THE    PLOW    AS   ADAPTED    TO    PURPOSES 

1.  Shape  of  mold  board  (Figs.  19,  20  and  21) 10 

2.  Selection  and  adjustment  of  coulter  and  jointer 1.5 

3.  Condition  of  wearing  surfaces  and  cutting  edges 20 

4.  Adjustment  and  hitch  of  plow 15 

5.  Weight 5 

6.  Draft 5 

The  Native  Power 

7.  Size  and  ability  of  team  to  do  work 5 

8.  Harness 5 


Condition  of  Soil  for  Plowing 

9.     Soil  in  proper  moisture  condition 

10.     Proper  depth  and  width  of  furrow 


Total . 


100 


Texture  and  condition  of  soil . 

Width  of  furrow 

Remarks: 


Dei)th 


-Sod  plow  which  does  not  pulverize  the  soil  very  much 


ng  and  gently  curved. 


(84) 


EXERCISE  32   (Continued) 


Fig.  20. — Stubble  plow,  with  a  steep  moldboard  abruptly  curved. 


.^ 


SHARE 


Fig.  21. — General  purpose  plow. 


Grade. 
Date. . 


EXERCISE  33  (85) 

Examination  and  Discussion  of  Tillage  ^Machinery 

(  Side  hill  or  reversible 
I  Landside  (walking) 

Plows \  Sulky  (one  way) 

I  Sulkv  (two  way) 
[  Di.sk 

(■  Full  disk  Spring  tooth 

Harrows I  Cutaway  Spike  tooth 

[  Spading  Acme 

Meeker 

f  Riding 
r».,if-   „f^-.  J  Coulter  (common) 

<^"^^'^'^*«'^^ 1  Spiketooth 

[  Spring  tooth 

a^;i  Tr;..,„r.^=  /  Solid  Roller  Packer  and  muloher 

Sod  I  irmers |  Corrugated  roller  Planker 

QUESTIONS 

1.  Make  a  drawing  of  a  section  of  each  one  of  these  harrows. 

2.  When  should  fall  plowed  land  be  harrowed? 

3.  When  should  spring  plowed  land  be  harrowed? 

4.  If  a  man  could  have  but  one  harrow  what  one  should  he  choose? 

5.  Under  what  conditions  would  each  cne  of  the  disk  harrows  give  the  most 

satisfactory  results? 

6.  If  a  soil  on  a  certain  farm  is  somewhat  uniformly  a  medium  loam  what 

two  harrows  would  be  the  most  economical  to  purchase? 

7.  Describe  the  work  of  the  Acme  harrow. 

8.  What  type  of  work  leaves  the  soil  the  lightest  and  loosest  and  which  one 

compacts  it  the  most? 

9.  Which  harrow  works  the  soil  the  deepest? 

10.  Which  harrow  is  adapted  to  the  interculture  of  crops? 

11.  Why  should  harrows  be  as  wide  as  possible? 

12.  What  are  the  advantages  of  the  corrugated  roller? 

13.  Wliat  are  the  advantages  of  rolling  and  when  should  it  ])e  done? 

14.  What  type  of  cultivator  is  the  most  popular  and  why? 

15.  ]\Iake  a  drawing  of  the  different  types  of  coulters  and  jointers  used  on 

plows.    State  clearly  the  use  and  value  of  each. 
10.  What  are  the  advantages  of  the  planker? 


(86)  EXERCISE  33   (Continued) 


EXERCISE  33   (Continued)  (87) 


•SBJ* 


^^s^' 


'>^V-i«.v. 


YD  16376 


